The invention relates to a microduct-tube winders for winding up extruded empty plastics microduct tubes having an outside diameter of about 2 to about 20 mm, having a reel which is rotatable about a rotation axis and has a core arranged between two radially projecting flanges, the tube being preferably windable on said core in several layers, and having a movable tube guiding device preferably upstream of the reel, via which the tube is fed to the reel, wherein a first transfer point is provided on the tube guiding device, the tube losing contact with the tube guiding device at said first transfer point in the operating state of the microduct-tube winder, and wherein provision is made of a second transfer point, assigned to the reel, the tube coming into contact with the core or a tube layer wound onto the latter at said second transfer point. Microduct-tube winders can also be designated as winding units, by means of which empty plastics microduct tubes are able to be wound on reels.
Devices are already known from the prior art for the producing and storing of windable plastic tubes, for instance from DE 296 12 732 U1. There, a system with a continuously operating extrusion device for the production of plastic tubes is disclosed, which is provided with a downstream winding device for the produced plastic tubes. Here, between the extrusion device and the winding device, an intermediate storage device is used for the intermediate storage of the continuously extruded plastic tube when the winding device is stopped.
In the processing of metal cord, which is formed from a plurality of single wires, the use of single twist cable-making machines is also known. Thus, for example, DE 196 14 404 C1 discloses a single twist cable-making machine with an open stranding rotor in which, on both sides of a reel, plates are placed on corresponding openings of reel walls and a means transferring at least tensile forces acts on the plate lying further distant from the drive of the reel.
Close prior art is also known from DE 43 40 360 A1, in which a method and a device is disclosed for the intermediate storage of strand-shaped material.
Methods and devices for the compensatory storage of packaging tape in packaging machines is also known from EP 0 139 088 B1. However, it is located in a different technical field, namely that of packaging tapes.
DE 20 2005 004 817 U1 also is not concerned with empty plastics tubes, even less with empty plastics microduct tubes, but rather with threads, in the context of which a dancer control is disclosed. Here, a double spindle winder is used for the continuous winding of threads, which enables a thread change from a first spindle to a second spindle in continuous operation, wherein the thread is fed to one of the spindles by means of a laying device, wherein in addition the two spindles are arranged adjacent to one another with offset spindle axes aligned in a parallel manner, and the thread is fed to the laying unit via a thread tension control.
The invention also concerns double station winders with two microduct winders, wherein fully automatic double winders are already used in other fields of application in high-performance extrusion systems with high extrusion speeds.
Frequently, three-phase motors are used for the drive, which are dancer-controlled or are regulated via tensile force. The laying is possibly synchronized with the rotation speed of the winder drive and can be adjusted continuously. A strapping of created coiled bundles with bands is known hitherto, likewise the wrapping of the coiled bundles in foils. Here, now and again, combination winders are used, or those which are suitable for the radial wrapping of the bundles in foil. The use of automatic winders for packing the coiled bundles directly into cardboard boxes is likewise known.
Microduct-tube winders with securely fixed winding stations and a displaceable, movable laying arm are usual. The laying arm then moves transversely to the feed direction of the microduct tubes. Unfortunately, a large amount of play occurs here and results in inaccuracies which entail a poor laying pattern. In extreme cases, even a winding interruption can occur. Hitherto, only very short coil lengths are possible, until an error occurs. In order to prevent these problems, manual laying is frequently resorted to, which, however, is not CE compliant. Also, here, only speeds up to 50 m per minute are possible, which therefore has a highly efficiency-inhibiting effect.
Despite everything, the winding result is hitherto if anything defective because flaws or cross-overs of the tube are still possible. “Flaws” are understood here to mean that the tube does not adjoin seamlessly in transverse direction onto a previously laid tube section and thus a gap occurs.
A “cross-over” is understood as a crossing of two tube sections. Such a cross-over can entail a kink in the tube. The passage through the empty space of the plastics tube is then no longer possible or no longer possible in an uninhibited manner. Electric lead elements such as glass fibres can then no longer be introduced, for instance blown in, into the empty plastics tube. The “blow-in lengths” in this regard are thereby greatly reduced.
Small tube diameters of approximately 3 or 4 to approximately 10 mm can at present not be wound automatically at all, without resorting to a manual intervention. However, this then results in an increased safety risk for the operating personnel.
The problems, as presented above, also further intensify through the use of low-cost reels, which are mostly constructed based on wood or plastics or respectively now and again based on metal, such as steel. The dimensional accuracy of such reels is hitherto poor, bearing in mind the desired cost reduction. With the use of existing winding units, the problems identified above then occur in an increased manner.
Attempts were made to use upstream magazines, for example of the pneumatic type of actuation, whereby the coil change times are to be bridged. “Coil change times” is understood to mean the time which is required for changing a reel fully occupied with tubes up to the end of the inserting of a new, tube-free reel. However, such magazines frequently have the disadvantage that a winder or a downstream belt-type haul-off draws the tube through the magazine and therefore the tube undergoes an elongation, which is undesired, because this is detrimental to the precision of the tube.
Even in the case of changes to existing winders, in the case of very small microduct tubes at high speeds, no satisfactory results could be achieved. Very small microduct tubes are those tubes which have a tube outside diameter of ≤2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm or 20 mm. Intermediate sizes are, of course, also included here. Such empty plastics microduct tubes have here a wall thickness of approximately 0.6 mm to 2 mm. This wall thickness is composed of the material thickness due to the plastics material and of a ribbing or silicone coating, present on the inner side, of approximately 0.15 mm. The ratio of weight to meter in kilograms per meter is between 0.0145 to 0.1115. Usual outputs are 104 kg per hour to 421 kg per hour. The withdrawal speeds vary between 63 m per minute, 80 m per minute, 108 m per minute and 120 m per minute.
“High speeds” are understood to mean speeds of 100 to 125 m per minute and beyond, for instance in the region of ≥200 m per minute.